ZTE Corporation

zVOA: Build Unified Voice and Multimedia Network, Enable Convergent Operation

With the fast development of smart phone and mobile broadband, mobile network has stepped into the mobile internet age. But, the position of mobile operators in the industry chain is declining, while the position of internet operators is rising.

Currently mobile operators adopt CS+IMS dual core networks for operation. In this, mobile softswitch network provides voice/SMS/USSD and other services for 2G/3G terminals, and IMS provides multimedia service for broadband terminals of 3.5G/LTE/WiFi, etc.

CS service is still main source of revenue in short time. However, with the fierce competition of Service Providers (for example: google, skype, etc), the mobile operators’ revenue flow is decreasing in long term. Although IMS can provide various multimedia services and enhances the telecom network capabilities, but its architecture is too complicate to evolve existing network easily. Presently, IMS has not involved in any new cash flow.

As it is a long procedure for mobile network evolving from 2G/3G to 4G, CS network and IMS network will co-exist for a long term. If adopting the dual network operation policy, mobile operators will be at a negative competition position.

With the deep understanding on mobile network and ten years of experience in the softwitch and IMS R&D, ZTE proposes the CS&IMS convergence solution, ZTE’s Voice & Video over Any Access (zVOA). It adopts one set of equipment, which controls both voice and multimedia networks, and provides services for  traditional terminals and Smart terminals, as shown in Figure 1 below.


Figure 1 zVOA Solution Networking

zVOA meets users’ requirement of multiple accesses and service call continuity (SCC). It is compatible with all the standard interfaces of CS and IMS. This solution applies to the migration of voice service from traditional terminal to smart terminal, and greatly simplifies IMS network deployment. In this solution, IMS network only needs two devices, iCX+iMG, to provide service as simply as CS.


  • Innovative and high integrated products: iCX(intelligent Controller eXtensive) and iMG(integrative Media Gateway). With iCX and iMG based on ETCA platform, softswitch domain and IMS domain share the same hardware. The hardware resources such as CPU, Memory, and Ethernet interface form a pool, which is shared by both CS and IMS. Despite the traffic is in CS domain or migrated to IMS domain, system processing capability is fully used, reducing the network transformation and investment.
  • zVOA realizes the equipment convergence as well as deeply service convergence of CS and IMS NEs, achieving innovative VoLTE solution.
  • zVOA provides service access modes of 2G/3G/4G/WiFi/PON. Despite terminal or access mode used by user, system service processing is always on the iCX and iMG. Thus it is easy to provide one number service, ensuring user seamless roaming between different access networks.

In the future, zVOA continues developing to build SNS network. It will provide rich communication capabilities for various terminals in all kinds of access networks, build the mobile communication network to be a powerful SNS network, offer perfect communication experience to users, and help operators improve competitiveness in the mobile internet age.